I recently reviewed a new paper that looks at adverse events in the injectable drug, Librela, also called bedinvetmab. This medication is widely used to help dogs with arthritis pain. Many dogs feel and move better after receiving it. However, this paper highlights some rare but serious joint problems that we need to be aware of.
You can read the full article here: https://www.magonlinelibrary.com/doi/10.12968/coan.2026.0009
The Good and the Concern
Librela works by blocking a pain signal in the body called nerve growth factor. When that signal is blocked, dogs often feel much more comfortable and become more active.
The concern is that in rare cases, some dogs may develop significant joint problems after treatment. These problems are not common, but when they happen, they can be severe.
My Perspective
In my opinion, we are not seeing brand new diseases being created by this medication.
Instead, what we are seeing is a drug class effect. Medications like bedinvetmab in dogs and frunevetmab in cats, also known as Solensia, are part of a group called anti-nerve growth factor monoclonal antibodies.
What I believe is happening is that these drugs may accelerate the very condition they are designed to treat. In some cases, that acceleration is so fast and so severe that we can clearly see it on X-rays .
That does not mean the disease is new. It means the timeline has changed.
Two Types of Joint Problems Seen
The paper describes two main patterns.
1. Rapid joint breakdown
This is when a joint gets worse very quickly. The cartilage and bone can deteriorate faster than expected.
2. Slow but abnormal bone growth around the joint
This happens more gradually. The body forms extra bone in and around the joint where it should not be.
This second type can be harder to notice early because the dog may still feel good due to pain relief.
Why Might This Happen?
We do not fully know yet, but there are a few likely reasons.
- Dogs feel better and move more, which can overload the joint
- Blocking nerve growth factor may change how joints repair themselves
- The body’s natural healing system may not work the same way
When you combine these factors, it may speed up joint damage in certain patients.
A Quick Thought on X-rays
In some of these cases, the changes are so dramatic that we can clearly see them on X-rays.
But it is important to remember that X-rays do not always tell the whole story. They are just one method when evaluating joint health.
Soon, I’ll publish a separate post that dives deeper into what X-rays can and cannot tell us.
Why This Matters
Pain relief does not always mean the disease is improving.
Dogs can look better on the outside while the joint is getting worse inside.
What Should We Do Differently?
This paper highlights a few important steps.
- Take X-rays before starting treatment
- Repeat imaging over time
- Watch for changes in movement or stiffness
- Recheck the joint if the medication seems to stop working
These steps help catch problems earlier.
Final Thoughts
Given what we are seeing, it is fair to ask a harder question.
This same class of drugs was halted in human medicine years ago because of very similar joint-related safety concerns. When we start to see comparable patterns in our veterinary patients, even if rare, we have to take it seriously.
In my opinion, we should reconsider whether these drugs should be used at all, or at the very least, used far more cautiously than they currently are.
Our goal is not just to reduce pain in the short term, but to protect joint health and quality of life in the long term.
drbrunke 
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